Se/Ni interactions are one of the easiest things in Socionics for me to see, but one of most difficult things to explain.
ESFps seem to tease less. When they're playful, it's in a lighter, more energetic and open way. They're much more direct, too.
ISxjs seem to tease more, often by challenging something you've said or done, sometimes to the point of nitpicking. They try to drag you into a debate or a challenging exchange of sorts. It's not all that serious though, depending on the subject matter and the individuals involved. The way they act appears to be challenge-seeking (rather than malicious). I think that's part of the reason they seem so critical to most people... they're just trying to find out if you're strong enough or interesting enough or smart enough to respond a certain way.
In Beta this takes the form of arguments. In Gamma this takes the form of mutual criticism that's intended to be useful (instead of drama), though I think it's more for stimulation between ENTjs and ISFjs than it is between ESFps and INTps, who just say it because that's just what they think. (I think they stimulate each other with Fi and Te instead of Ni and Se, which would make sense with my theory/observation/understanding that the 2nd/6th functions give a relationship energy and the 1st/5th functions give it stability.)